On my '98 Yukon slt 4x4, My brakes felt spongy. It felt like I needed to bleed the brakes. However, no matter how much I pumped the brake, no fluid, bubbles, or even air, would come out of the bleeder nipple. I fugured it might have been the cylinder inside the brake drum causing the problem, so I disconnect the brake line from the drum entirely. I try pumpkin again, only to get the same result. I asked my dad what the problem might be, and he said it could be a clogged/pinched line, the abs system, or the master cylinder. How would I go about testing these theories? If I needed to get a new master cylinder, would I need a new reservoir or can I reuse the old reservoir on the new cylinder? My dad also said that we could bypass the abs system lines entirely, and just live without abs (I'm sure the system doesn't work anyway, the abs light has been on since we got the truck a several years ago). Any help is much appreciated.
(Note: I tried bleeding the rear drum brakes. I am certain that the front ones get fluid because they stop the truck when I press on them, I just get the spongy feeling from the brake pedal (sometimes the pedal gets harder to push when I repeatedly press on it, but sometimes it never build up resistance). Also note that I am not currently driving this truck on the road, so don't freak out about me driving around with only front spongy brakes)
(Note: I tried bleeding the rear drum brakes. I am certain that the front ones get fluid because they stop the truck when I press on them, I just get the spongy feeling from the brake pedal (sometimes the pedal gets harder to push when I repeatedly press on it, but sometimes it never build up resistance). Also note that I am not currently driving this truck on the road, so don't freak out about me driving around with only front spongy brakes)